This invention relates to a triggering arrangement for restraint systems in motor vehicles of the type wherein acceleration dependent switches activate an electrical signal which in turn activates a pyrotechnic device to act in the restraint system component. A triggering arrangement of this type is known from German Published Unexamined Application No. 26 31 190.
In the case of the arrangement known on the basis of German Published Unexamined Application No. 26 31 190, an electronic unit is supplied by the electrical system of the motor vehicle and has two sensors and an igniter arranged in a shielded housing at a central point in the motor vehicle. Fast-burning fuse cords lead from the electronic unit to belt-tightening devices at the motor vehicle seats.
From German Published Unexamined Application No. 26 31 190, an acceleration sensor is known that is also supplied by the electrical system of the motor vehicle and that, together with a storage capacitor and an igniter, is housed in a shielded housing.
In the case of these arrangements, the current supply from the electrical system of the motor vehicle is costly and susceptible to disturbances and must be shielded from high-frequency radiation and other interfering signals coming from the outside. The triggering arrangement is connected with the electrical system of the motor vehicle by means of costly cable trees. Unfavorable cable lengths have the effect of an antenna, capture interfering high-frequency signals and require increased protection in order to maintain the operability of the device. Often expensive plug-in systems are required in order to ensure the operability of the triggering system. However, just as costly and susceptible to interferences are the fuse cords that lead from a joint igniter to the individual driving assemblies of the belt tightening devices.
It is therefore an objective of the invention to further develop the known device to the extent that expensive cables and cable trees and costly electrical connections are avoided and that a triggering arrangement is provided that is as cost-effective as possible and is largely unsusceptible to interferences of all types.
According to the invention, this objective is achieved by providing common shield in housing for the pyrotechnic device igniter, and actuating circuit with acceleration dependent switch means.
The special advantage of the invention is the fact that it can be completely assembled outside the vehicle, that no connecting cables are required by means of which interferences can be captured and that no electrical connection is required to the vehicle, also not to the electrical system of the motor vehicle. As a result, the triggering arrangement according to the invention is especially suitable for being installed in child's seats.
Further objects, features, and advantages of the present invention will become more apparent from the followinq description when taken with the accompanying drawings which show, for purposes of illustration only, an embodiment/several embodiments in accordance with the present invention.